Offsetting-press



ATTORNEY 3 SHEETSSHET I.

12- -L Iii Patented May 11, 1920.

H. MILLER.

OFFSETTING PRESS.

APPLICATION FILED mm. a0. 1918.

WITNESSES:

H. MILLER.

OFFSETTlNG PRESS.

APPLICATION man MAR- 30. 1918.

1,340, 1 38, Patented May 11, 1920.

3 SHEETSSHEET 2.

WITNESSES: INVENTOR ATTORNEY 3 H. MILLER.

OFFSETTING PRESS.

APPLlCATiON mm mm 3 ms.

Patented May 11, 1920.

Fig. =3.

.Tiig

DH 0 N E v N ATTORNEYJ UNITED STATES PATENT OFFICE.

HENRY MILLER OF MILWAUKEE, WISCONSIN, ASSIGNOR TO A. 0. SMITH CORPORA- TION, OF MILWAUKEE, WISCONSIN, A CORPORATION OF NEW YORK:

OFFSETTING-PRESS.

Application filed March 30,

To all LUhOIIt it may concern:

Be it known that I, HENRY M'ILLEB, a citizen of the United States, residing at the city of Milwaukee, county of Milwaukee, and State of \Visconsin. have invented new and useful Improvements in Offsetting- Presses, of which the following is a specification.

My invention relates to improvements in offsetting presses for sheet metal blanks.

One object of my invention is to provide means for exerting pressure against the edge margins of a sheet metal blank or set of blanks in such a manner as to distort the blank laterally between the planes of its flat or side surfaces, thereby converting .a flat strip or sheet of metal having straight side margins into a strip or sheet having approximately the same thickness, but with one side margin indented or pressed in wardly and the other side margin correspondingly bulged or pressed outwardly, without otherwise distorting the stock.

Another object of my invention is to provide improved means whereby a strip of sheet metal of a certain gage. (a. thick ness) may be clamped and subjected to edge pressure in such a manner as to produce a sheet or strip of different thickness or of differing thicknesses in different portions thereof.

My invention is of peculiar value in the manufacture of sheet metal frame bars for motor driven vehicles and other metallic frames in cases where the completed bars are curved at one end or at points intermediate of their ends, and also in cases where it is desirable to form a bar from sheet metal with one portion thin and wide.

and another thick.

I not only provide means for producing a blank of the required size. thickness, and contour in a single operation performed upon an originally rectangular strip or sheet of metal, but I also contemplate the provision of means whereby bending operations may be performed simultaneously upon a series of suchstrips by means of a single press so arranged that the blanks maybe readily removed after a bending operation and another set of blanks inserted during the short interval that the pressing portion relatively narrow and Specification of Letters Patent.

1918. Serial No. 225.791.

head is retracted in a machine which is being continuously operated.

The offsetting press herein disclosed is designed to effectuate the processof bending metal plates in the direction of their width, as claimed in application Serial #370,136. filed March 30, 1920, by B. Stallley Smith.

In the drawings Figure 1 is a side elevation of a press embodying my invention.

Fig. 2 is a plan view of the same.

Fig. 3 is a fragmentary view of the stationary and movable members of a vertically acting drawing press embodying my invention. in modified form.

Fig. 4 is a fragmentary view of a further modification.

Fig. 5 is a plan view. on a reduced scale, of a strip of sheet metal as it appears preparatory to the pressing operation.

Fig. 6 is a view of the same after it has been subjected to an offsetting operation in my improved press.

Fig. 7 is a view of a blank formed from a strip of metal like that shown in Fig. 5. in which the press has been used to both bend and thicken portions thereof.

Like parts are identified by the same reference characters throughout the several views.

In Figs. 1 and 2. a table 1 is supported from a bed 2. and is provided in its upper surface with a table plate 3 adapted to receive the work, comprising a blank, or, if desired. a set of sheet metal blanks 4. The table is provided with an upwardly projecting shouldered portion 5 near its front end. against which a stationary matrix is seated. This matrix preferably comprises a separate or separable member interchangeable with other and similar matrices of differing thickness and contour, but it is not essential to my invention in its broader aspects whether .the matrix be separable or integrally formed. The inner margin of the matrix constitutes a work shaping face or die. and in the construction illustrated in Fig. l. the matrix is of sufficient thickness to receive several sheet metal blanks 4. the latter being placed in a horizontal position upon the table plate 3 with their edges substantially in abutting contact with th 'matrix, and in the more rearwardly projected portions of the die.

The contour of the die corresponds, of course, to the desired edge contour to be 1mparted to the blanks.

A movable die member 7 is actuated along the table late 3 b means of a clamping head 8. his move le member has a working face which inversely conforms in contour to the contour of the working face of the matrix, and it is arranged to bear against the work in direct opposition to the lane of the work. Where the matrix is interchangeable with others of the desired contour or thickness, the movable die members 7 will also be made removable from the head 8 and interchangeable with others corresponding, in each case. with the substituted matrix in thickness and also inversely as to contour.

In the construction shown in Fig. 1, the

clamping head 8 is connected with a slide 10, which is loosely interlocked with the table 1. The head 8 has a shouldered portion 12, against which, the rear margin of the die member 7 is seated, whereby, when the clam ing head is moved forwardly, the die mem er will be brought into pressure contact with the work.

' The clamping head 8 is provided with a forwardl pro ecting work clamping portion 14, t e under surface of which is preferably provided with a removable face or platen 15 ads ted to bear upon the up er surface of'a b ank 4 supported by the ta le plate 3 between the die members, the die having substantially the same thickness as that of the blank, (or pile of blanks if more than one blank is to be shaped in a single operation). It is not essential, except for the purpose of interchangeability. and replacement whether the face plate 15 and shouldered portion 12be separately formed or whether these (partake formed integral with the headS an with the die member 7.

The clamp head 8 may be actuated from any suite is source of power exerted obliquely to the upper surface of the table and in the direction of the matrix, or stationary die member 6. In the construction illustrated, the power is applied from a driving-pulley or wheel 20 throu h shaft 21, pinion 22, gear wheel 23, shaft 54, pinion 2:), gear wheel 26, shaft 27, eccentrics 28, carried b shaft 27, and connecting arms or rods 2 the latter being pivotally connected with the clampinghead 8 by cross pins or bolts 30, whereby a slow but powerful reprocatlng movement is transmitted to the ead 8. The length of the stroke is suflicient to withdraw the clamping head from the work during the' retractive stroke, the

clamping head being then in the position indicated dotted ines in Fig. 1. The blanks will therefore be uncovered and they may then be removed and another set of blanks substituted preparatory to the next forward movement of the clamping head. The latter returns to the blank covering position before the movable die member 7 commences to exert effective pressure upon the blank or blanks.

Referring to Fig. 3, it will be observed that my invention is also applicable to an ordinary drawing press having a vertically reciprocating plun er. This may be accomplished by provid ng the bed 35 of such press with a work holder 36 having an u wardly extending oblique wing flange 3%, the front or work receiving face 38 of which terminates at it slower margin in a shoulder 39 projecting at right angles thereto. In this construction, the stationary die member or matrix 41 is supported u )0" the shoulder 39 and against the inclined iace 38. It has a contoured shoulder 40 to receive the lower edge or edges of the work and a thinner rtion 41' extends upwardly along the inclined surface 38 and forms a bearing surface for the flat side of the blank corres onding with the bearing surface afforded y the table plate 3 in ig. 1

The plunger 42 in Fig. 3 is rovided with a depending head 43 carried y a slide.44.v The latter is adapted for horizontally yielding movement along theslide way provided on the plun er, such movement, however, being resistec by a compression spring 45, which normally pushes the slide against a stop 47. The head 43 is provided with an inclined face 48 which is parallel with the inclined face 38 of the matrix and work holding member, and the movable die or tool 49 is secured to this inclined face near its upper margin. This die member also has a contouring shoulder {30 and a work clamping ortion 51, the latter corresponding functionally with the plate 15 in Fig. 1.

The. arrangement is such that, when the plunger 42 is depressed, the work clam ing portlon 51 of the die will move into sli ing contact with the blanks. 4", and thereafter the die shoulder 50 will engage the upper margins of the blanks and force them downwardly in the direction of the matrix 41. During this shaping movement, slide 44 will be retracted from stop 47 against the tension of the spring or springs 45, thereby allowing the head 43 to continue the downward movement until the blanks have been forced to conform to the contours of the opposing shoulders on the die members.

When the plunger 42 is retracted, the blanks will, of course, be released. The shaped blanks may thereupon be'removed and replaced by other blanks preparatory to the next downward movement of the plungle r.

In ig. 4, I have illustrated a form of construction in p which a relatively fixed die member 54 is provided with a vertical face 55, and a contouring face or shoulder at 56. The movable member 58 is in the form of a vertically moving plunger having a contouring face at 59 and a work clamping face at 60. The plunger operates between the fixed die member 54 and an upwardly projecting arm 6:. carried by the support or table 63, the latter having another arm or shouldered projection 64, against which, the die member 54 bears. This construction may be employed for relatively thin or soft stock, and in cases where a thickening of the stock as shown in Fig. 7 is not desired. It is, of course, possible to allow some yielding movement of the member 58 and also of its backing 62. but if yielding movements are desired. the forms of construction shown in Figs. 1, 2 and 3 will be found to be much better adapted for this work.

My invention is peculiarly adapted for shaping elongated strips of sheet metal, such as are used in manufacturing side bars for automobile frames. Fig. 5 illustrates one of these blanks as it appears preparatory to the contouring operation performed by my improved press. Fig. 6 shows the same blank after it has been subjected to the shaping or drawing operation.

In Fig. 7. it will be observed that the completed blank has been thickened at a and b. lhis is accomplished by so contouring the die members as to force a redurtion in the width of the strip along the portions which it is desired to thicken, whether the portion is offset or not. The pressure exerted upon a given area of the material by the movable die member is greater than that exerted upon an equal area by the clamping member or platen, and the latter is adapted to yield resiliently under pressure developed by the thickening of the material.

\Vhile I prefer to apply the poweralong lines oblique to the die faces, as indicated in Figs. 1, 2, and 3, in .order that the resistance of the clamping platen may automatically increase in proportion to the offsetting pressure applied to the movable die, it will be understood from Fig. 4 that this is not essential. It is also not essential that either die member should be formed as a separate or separable member from the shoulder or member against which it is placed. although I prefer to use separate die members in order that they may be re placed or interchanged with other members of differing contour.

From the foregoing description. it will be obvious that my invention may be utilized to thicken a blank without changing the contour of its edge margins by using dies having edge engaging surfaces which fit the margins ofthe blank throughout their length. In such cases. a rectangular blank will remain rectangular and will be reduced in width and increased in thickness. My invention also may be utilized to change the edge contour of a blank from that illustrated in Fig. 5 to that illustrated in Fig. 6 without materially altering the width or thickness of the work. or if desired, variations in contour. thickness. and width may be made in a single operation.

My invention also provides means whereby the movable member may be made sufl'i- (iently thick and strong to withstand all strains to which it may be subjected during a shaping operation, for the reason that the pressure applying head is not limited in thickness to the thickness of the stock, but includes also the thickness of the portion which laps upon the flat surface of the work and exerts a clamping pressure thereon. Even in the construction illustrated in Fig. 4-. a clamping pressure is developed as soon as the work starts to thicken or buckle under the pressure exerted by the shoulder 59. The movable member in this construction is not only reinforced by the table projection 62, but it is also made sufiiciently thick and heavy to avoid any possible danger of breaking above the point where it enters the space between the projection 62 and the relatively fixed die member 54.

In the form of construction shown in Fig. 4. the movable head 58 is preferably recessed on its outer side, as indicated at 65. to reduce friction upon the proje'tion (l2.

'hile I have, for convenience in description. referred to the clamping head in Figs. 1. 2. and 3, as constituting a different element from that which is designated as the movable die member, it will be understood that. broadly speaking, the head is a part of" the die member, and these parts may. as above stated, he formed integrally. The same is true as to the fixed die member and the table or table plate 3.

It is possible to use the same press for contouring blanks without materially thick ening them. and for thickening them either throughout their length or in certain portions. and either in connection with contouring operations involving changes in marginal outline or otherwise. the results beiug dependent in part upon the form of the dies used and in part uponthe length of the work shaping stroke. i. (a. the degree of movement of the movable die after the work shaping operation commences.

\Vhere any portion of the blank is being offset in such a manner as to change its marginal contour. there will be little. if any tendency to thicken it until the shouldered portions of the dies. which engage the edges of the blank, are in pressure contact. and with substantially equalized pressure. along the portion which is being offset for such contouring operations. In such cases, there will be some tendency for it to become thicker along the central portion of a margin which is bending concavel and there will be some tendency for it to become thinner along a margin which is bending conyexly, but this is true of all bending operations, and it is only where the pressure is continued after the stock has conformed to the contour of the die that a tendency will develop for the stock to thicken throughout its width and develop ressure sufficient to cause the platen to yie In contouring flat plates, there is little tendency for the material to extend longitudinall at right angles to the direction in which t e pressure is applied owing to the fact that not only the clamping pressure, but also the pressure developed along parallel lines throughout the entire length of the blank, sets up counter pressures at all points. except at the extreme ends. Therefore if the pressure is continued after the edge engagmg'shoulders of the dies are not only in contact with thework throughout their length, but in substantially equalized pressure contact, the blank will then become thickened throughout its length and width. But if-in one portion of the blank, the edge ressure contact becomes equalized, while in another portion offsetting movements are permitted, owing to the contour of the dies, then a continued movement of the movable die will offset where offsetting movements are permitted, and will thicken the work in the area where no further ofl'setting can take place.

. I claim 1. In an offsetting press for sheet metal blanks, the combination with a set of relatively fixed and movable clamping members ada ted to engage the side edges and flat sur aces of said blanks, and means for actuating one of said members against the edge of the blank and along one of its flat surfaces, to offset the blank bodily.

2 In an offsetting press adapted for contouring sheet metal blanks, the combination of a work support provided with a contouring die face to receive one edge of the work, a movable member provided with a correspondingly shaped contouring die face to bear upon the opposite edge of the work, and also having a portion which overlaps the work and is adapted to cooperate with the work su port in resisting movement of the materia of which the work is composed, in any other direction than that permitted by the contour of said die faces:

3. In an offsetting press, the combination of two correspondingly contoured work shaping members, each adapted to bear u 11 work in a plurality of intersecting p anes, and to exert pressure upon the work in opposition to the caring surfaces of the other member, means for actuating one of said members to effect a relative approachof one of its bearing surfaces toward one of the bearing surfaces of the other member while maintaining the other bearing surface of the respective members in uniformly spaced relation, whereby the work may be shaped by pressure developed by the approaching surfaces while the work is clamped between the other surfaces of said members.

4. In an offsetting press for sheet metal blanks, the combination of two blank shaping members having correspondingly contoured faces adapted to engage the side edges of the blank between them and also having their faces adapted to engage the flat surfaces of the blank between them, and means for effecting a relative approach of the edge engaging faces while maintaining the other faces in substantially uniformly spaced relation to each other.

5. In amdffsetting press, the combination of two work shaping members having correspondingly contoured work shaping faces and also having opposing bearin faces in planes substantially at right ang es to the work shaping. faces and spanning the space between the work shaping faces, and means for causing the work shaping faces to approach and recede while maintaining the bearing faces in substantially uniformly spaced relation to each other.

6. In an offsetting press, the combination of a work support, relatively fixed and movable die members adapted to receive one or more blanks between them upon the work support, a clamping member adapted to bear upon the work, and also adapted to engage and actuate the movable die member, and means for applying pressure to the clamping member along an oblique line inclined to the support in the direction of the relatively fixed die member.

7. In an offsettingpress adapted for con touring sheet metal blanks. the combination of a work support, relatively fixed and movable die members adapted to receive the work between them upon said support, a clamping head adapted to bear upon the upper surface of the work, and also adapted to actuate the movable die member, and

means for applying ressure to the clamping head along an o lique line inclined to the support in the direction of the relatively fixed die member, whereby the work may be clamped upon the support and subjected to pressure between the die members until the edges of the blanks, composing the work, are contoured to correspond with the contour of the die members,

8. In an offsetting ress adapted for contouring sheet metal bl of a work support, relativel fixed and movable die members adapte to receive the work between them upon said support, a

anks, the combination I clamping head adapted to bear upon one flat surface of the work, and also adapted to actuate the movable die member, and means for applying pressure to the clamp ing head along an oblique line inclined to the support in the direction of the relatively fixed die member, whereby the work may be clamped upon the support and subjected to pressure between the die members until the edge of the blanks, composing the work, are contoured to correspond with the contour of the die members, said clamping head being provided with a guide slidingly interlocked with the support, and adapted to permit reciprocating movements of said clamping head.

9. An offsetting press, including the (CH1- bination of a work support adapted to receive the flat surface of a sheet metal blank, a matrix having a contoured margin, means for holding the matrix with its contoured margin in position to receive one side edge of the blank, a die member having a margin contoured as the counterpart of the matrix margin, and adapted to engage the other side edge of the blank, a clamping head adapted to engage the die member and move it in the direction of the matrix, and means for applying pressure to the clamping head along an oblique line inclined to the support in the direction of the matrix; said clamping head being formed to extend over the flat surface of the matrix in sliding contact therewith and clamping relation thereto.

In testimony whereof I aflix my signature in the presence of two witnesses.

HENRY MILLER.

'itnesses J. J. STAMM, C. FUCHS. 

